A transcatheter heart valve (THV) is a prosthetic, or replacement, heart valve which is configured to be implanted by a catheterization technique. One type of THV has been developed by Edwards Lifesciences of Irvine, Calif. and is described in U.S. Pat. No. 6,730,118, which is hereby incorporated by reference in its entirety. The THV described in the '118 patent is primarily configured for replacing the function of a stenotic aortic valve in a human heart. An important feature of the THV is the ability to be implanted within the stenotic region of the native aortic valve. After implantation, the THV holds open the leaflets of the native aortic valve and utilizes the native valve annulus as an attachment means for the THV.
Such transcatheter techniques traditionally involve the implantation of a prosthetic valve that can be compressed or folded to a reduced diameter. By compressing or folding the prosthetic valve to a reduced diameter, the prosthetic valve can be delivered through a less invasive penetration to a desired target location within the human anatomy. Thereafter, the compressed valve is traditionally released, expanded, separated from the delivery system, and secured to the desired target location.
An important design parameter of the THV is the diameter of its folded or crimped profile. The diameter of the crimped profile is important because it directly influences the physician's ability to advance the THV through the femoral artery or vein. More particularly, a smaller profile allows for treatment of a wider population of patients, with enhanced safety.
U.S. Pat. No. 7,381,219 (the '219 Patent) discloses a replacement heart valve having a replacement valve collapsed within the lumen of an anchor. Col. 7, lines 35-36. “Retraction of wires 50 relative to tubes 60 foreshortens anchor 30, which increases the anchor's width while decreasing its length.” Col. 7, lines 36-38. The '219 patent also discloses a two-piece apparatus comprising an expandable anchor piece and an expandable replacement valve piece. The anchor piece includes a groove section that is “adapted to engage an expandable frame portion” of the valve piece, in order to couple the anchor piece to the valve piece. Col. 17, lines 38-41. Such coupling can be complicated to perform and can make implantation difficult.
European Patent EP 1 872 743 discloses a cardiovascular valve assembly comprising a replaceable valve member and an expandable base member designed to account for patient growth. “After installation of base member 100, tubular body 110 may be dilated to a small diameter during a first procedure. A valve member 20 having a small diameter frame 30 can be docked with base member 100 by insertion of fingers 50 into opening 154.” Col. 7, line 57 to col. 8, line 4. Again, this method of inserting fingers into openings in the disclosed design can be complicated to perform.
International Application No. PCT/US2008/001590 discloses a valve having “a valve leaflet 104 that] can be coupled adjacent to the proximal end 112 of the valve frame 102 at junction points 120.” Page 4. A “leaflet transition member 110 [is] coupled to at least a portion of the valve leaflet 104 and/or the leaflet frame 111. Page 4. “Elongate push members” on a delivery catheter “can be used to push the leaflet transition member 310 inside the lumen 308 of the valve 300.” Page 10.
These replacement heart valves can be complicated to manufacture and/or implant within a patient's body. A need thus remains for an improved replacement heart valve that can address these and other disadvantages associated with conventional replacement heart valves.